1 files changed, 77 insertions, 0 deletions
diff --git a/tests/sdl_canvas_palette_2.c b/tests/sdl_canvas_palette_2.c
new file mode 100644
index 00000000..db051b2b
--- /dev/null
+++ b/tests/sdl_canvas_palette_2.c
@@ -0,0 +1,77 @@
+#include <stdio.h>
+#include <SDL/SDL.h>
+#include <emscripten.h>
+
+static const int COLOR_COUNT = 32;
+
+static SDL_Surface *screen;
+static SDL_Color   pal[COLOR_COUNT +1];
+
+void initializePalette() {
+  //initialize sdl palette
+  //with red green and blue
+  //colors
+  pal[0].r = 0;
+  pal[0].g = 0;
+  pal[0].b = 0;
+  pal[0].unused = 0;
+
+  for (int i=1; i< 1 + COLOR_COUNT; i++) {
+    pal[i].r = 255 / COLOR_COUNT * i;
+    pal[i].g = 0;
+    pal[i].b = 0;
+    pal[i].unused = 0;
+  }
+
+  SDL_SetColors(screen, pal, 0, 1 + COLOR_COUNT);
+}
+
+void animatePalette() {
+  SDL_Color temporary;
+  temporary = pal[1];
+  for (int i=2; i< 1 + COLOR_COUNT; i++) {
+    pal[i-1] = pal[i];
+  }
+  pal[COLOR_COUNT] = temporary;
+
+  SDL_SetColors(screen, pal, 1, COLOR_COUNT);
+
+  //refreshing
+  SDL_LockSurface(screen);
+  SDL_UnlockSurface(screen);
+
+  printf("yet another cycle\n");
+}
+
+int main() {
+  SDL_Init(SDL_INIT_VIDEO);
+  screen = SDL_SetVideoMode(600, 400, 8, SDL_HWSURFACE | SDL_HWPALETTE);
+
+  //test empty pallete
+  SDL_LockSurface(screen);
+  SDL_UnlockSurface(screen);
+
+  initializePalette();
+
+  //palette is red yellow blue
+  SDL_LockSurface(screen);
+  int size = screen->h * screen->pitch;
+  char *color   = screen->pixels;
+  int divider  = size / COLOR_COUNT;
+  int i = 0;
+  while (i < size) {
+    *color = 1 + (i / divider); //red
+    color++;
+    i++;
+  }
+  SDL_UnlockSurface(screen);
+
+  //Animation
+  printf("you should see red gradient animation\n");
+  emscripten_set_main_loop(animatePalette, 0);
+
+  SDL_Quit();
+
+  return 0;
+}
+